1. Field of the Invention
This invention relates to personal ornaments or fancy goods, and more particularly to such fastening parts as a slider, a clamper, a pull tab, a top and a bottom stop, a divider, and elements in a slide fastener and such personal ornaments as buttons, buckles, belts, pendants, and accessories including necktie pins, hatpins, bracelets, earrings, watch chains, etc. which have appearances of nickel tone or black nickel tone.
2. Description of the Prior Art
Generally, the personal ornaments like fastening parts, buttons, buckles, belts, pendants, and accessories produce a weighty sensation of silver color when they have appearances of nickel tone. Thus, the nickel tone is popularly adopted for these ornamental items on account of the ability thereof to impart sensation of high quality to the appearances of the items.
Japanese Patent Application, KOKAI (Early Publication) No. 4-74567, for example, discloses a personal ornament which has a background part and a pattern part severally formed of metallic coating layers of different colors. In the embodiment of the personal ornament cited in the specification of this application, the background part as a basis comprises a nickel plated layer and, therefore, has the appearance of nickel tone.
When the surface layer of a personal ornament is formed of nickel, it indeed assumes an appearance of nickel tone. If this personal ornament is such as to touch the user's skin directly or indirectly, however, it will entail the problem of possibly causing the user to contract metal allergy (nickel allergy).
When this nickel layer is formed by the electroplating technique, it assumes magnetism. Particularly, the fastening parts which use this nickel layer, therefore, possibly pose a problem in the needle detecting work. Specifically, when the fastening parts are sewn to textile articles, these textile articles are probed to determine whether or not the segments of broken needles remain therein. Since the nickel layers in the fastening parts are mistakenly detected by the needle detector because of their magnetism, the needle detector fails to operate accurately and reliably.